This invention relates to the spreading of web material which is subsequently to be cut, usually automatically, in accordance with a marker defined by information stored in a computer memory, and deals more particularly with a system for assisting a spreader operator in dealing with flaws encountered during the spreading of the web material.
The system of the invention may be used in various different industries where material is to be cut in accordance with predetermined markers to create pattern pieces subsequently joined by sewing or other means to produce finished articles. In the garment making industry, for example, textile webs are conventionally spread on a spreading table to form a multiple layered layup and such layup is thereafter worked on by a cutting machine controlled by stored marker information to cut out bundles of pattern pieces. Such automatically controlled cutting machines are shown for example by U.S. Pat. Nos. 3,887,903; 4,133,235, and Re. 30,757. In some cutting and spreading operations, flaws are not taken into account during spreading and if they thereafter appear in pattern pieces, such pieces are used to make second or irregular grade articles. However, in other spreading and cutting operations, an attempt is made to deal with flaws so that every bundle of pattern pieces includes an equal number of good pieces allowing all of the finished articles to be of first quality without any seconds or irregulars being produced.
The material spread may be preinspected in which case flaws are marked in some way, such as by circling with chalk and/or applying a marking clip or tag to the edge of the material, to make them readily apparent to the spreader operator. Other times, the material may not be preinspected in which case the spreader operator visually inspects it as it is spread or the spreading machine may include a device for automatically inspecting the material as it is spread and for providing an indication when a fault is encountered.
If the spreader operator has only limited information available to him concerning the marker, he may have to assume that every flaw falls in a troublesome or unacceptable area of the material requiring him to take some corrective action for every flaw, and the corrective action to be taken is usually quite wasteful of the material. As an alternative, the operator when encountering a flaw may stop the spreading operation and lay a paper drawing of the marker over the layup to determine whether the flaw falls in an acceptable or unacceptable portion of the marker and to decide on a way of dealing with the flaw which is most economical of material if the flaw falls in an unacceptable location, but this use of a paper marker is quite time consuming and inefficient. It is therefore desirable that some means be provided for quickly correlating the location of a flaw to the marker to be cut from the material and from such correlation giving the operator information assisting him in deciding whether the flaw is troublesome and telling him how to deal with it if it is troublesome.
Prior U.S. Pat. Nos. 3,540,830 and 4,176,566 show two arrangements for providing flaw handling assistance to a spreader operator. In both of these disclosures, use is made of a transparent film strip containing a reproduction of the associated marker. The film strip is advanced with the web material as it is spread and is used with a projector which projects a portion of the film strip onto the material web in such a way as to produce on the material web a pictorial representation showing images of the pattern pieces to be cut from the web which images register with the pieces as they are subsequently cut from the web. Such systems, however, require the costly making of the film strips and rely on precise mechanical advancement of the film strip with the spreading of the material which precise mechanical advancement is difficult to maintain.
The general object of the invention is, therefore, to provide a system for assisting a spreader operator in dealing with flaws which system is one which may be implemented in various different ways depending on the requirements of its application and which, if desired, may be implemented in a very inexpensive way, all implementations using a computer memory resident marker representation, which memory resident marker representation may be the one also used to control the automatically controlled cutting machine driving the subsequent cutting operation, so that no additional marker representation need be prepared for the flaw handling system. The invention further aims at providing a flaw handling system which is otherwise an improvement over those shown by the two above mentioned patents with regard to cost, accuracy, versatility, ease of operation and other factors.
A further object of the invention is to provide a system of the foregoing character whereby through the use of a computer, the spreader operator may be provided with information defining the optimal way, insofar as saving of material is concerned, to deal with a flaw.
Other objects and advantages of the invention will be apparent from the following detailed description of the preferred embodiments and from the accompanying drawings.